Overview

This study will assess the safety, reactogenicity and immunogenicity of a single dose of Comvigen (Bivalent, ChulaCov19 BNA159.2) vaccine or BIVALENT Pfizer/BNT vaccine as a booster among healthy males and non-pregnant females aged 18-64 years after receiving a previous booster dose of any approved mRNA COVID-19 vaccine for more than 3 months. The results of Combiven will be compared to BIVALENT Pfizer/BNT vaccine.

Eligibility

Inclusion Criteria:

        Participants who meet all the following criteria at Screening are eligible to participate
        in the study:
          1. Must be a male or female aged 18 - 64 (inclusive) at the time of enrolment
          2. Must have completed at least a primary course of 2 doses of any approved COVID-19
             vaccine which the last dose have to be mRNA vaccine and completed the last doser 3
             months or more
          3. Must be able to communicate effectively with study personnel and considered reliable,
             willing, and cooperative in terms of compliance with the protocol requirements
          4. Participants must sign the written informed consent form prior to undertaking any
             protocol-related procedures
          5. SARS-CoV-2 rapid antigen test is negative at Day 1 (the day of receiving the study
             booster dose)
          6. Does not intend to receive any other authorized/approved COVID-19 vaccine at the time
             of enrolment and up to 3 months of the study
          7. Males must be surgically sterile (>30 days since vasectomy with no viable sperm),
             practice true abstinence or, if engaged in sexual relations with a female of
             child-bearing potential, the participants and their partner must use an acceptable,
             highly effective, double-barrier contraceptive method* from Screening and for a period
             of at least 60 days after vaccination
          8. A female participant is eligible if she is not pregnant, or breastfeeding indicated by
             one of the following conditions:
               1. With childbearing potential (WOCBP): she agrees to use an effective contraceptive
                  method or abstinence from at least 4 weeks prior to the study intervention
                  administration until at least 12 weeks after the study intervention
                  administration, or
               2. With non-childbearing potential. To be considered of non-childbearing potential,
                  a female must be post-menopausal for at least 1 year or surgically sterile
          9. Participants must be in general good health* based on medical history and physical
             examination, as determined by the PI at Screening.
         10. Participants must agree to refrain from donating blood, plasma, ova, sperm, or organs
             during the whole study.
        Exclusion Criteria:
        Participants who meet any of the following criteria are not eligible to participate in the
        study:
          1. History of a systemic hypersensitivity or life-threatening reaction to a vaccine
             containing any of the same or similar substances.
          2. History of test-confirmed by PCR or rapid antigen test to SARS-CoV-2 COVID-19
             infection within 3 months prior to randomisation.
          3. Presence of clinically significant medical history*, unstable chronic or acute disease
             that, in the opinion of the PI, may increase the risk of exposure to the
             investigational vaccine
          4. History of having any significant side effects after receipt of any other COVID-19
             vaccine eg. endocarditis, pericarditis or myocarditis. History of any severe
             reactogenic side effects or other medical illness that were thought to be associated
             with vaccine.
          5. Presence of an acute illness* or with fever at 38.00 C or more within 72 hours prior
             to vaccination.
          6. Bleeding disorders or taking an anticoagulant or anti-platelet agent that may
             contraindicate for intramuscular injection based on Investigator's judgment
          7. Inadequate venous access to allow the collection of blood samples.
          8. Received any prophylactic or therapeutic vaccine, biologic product, device or blood
             product, within 4 weeks of vaccination or 5 half-lives (whichever is longer) or
             anticipate doing so in the follow-up period defined for this study. For influenza
             vaccine, however, can be administered up to 14 days prior to randomization and
             following visit 3 (Day 29+3) after blood sample collection.
          9. History of ever had an anaphylaxis reaction to food, medication, or vaccination.
         10. Participant is immunosuppressed as caused by disease or immunosuppressive therapy or
             anticipated need to use of any chemotherapy or immunosuppressive agents* within the
             next 6 months.
         11. Participation in any of the other investigational trials of vaccines, therapeutic, or
             medical devices 12 weeks before or during the 6 months of this study.
         12. Received immunoglobulins and/or any blood or blood products within 3 months before
             vaccination day or plans to receive any blood or blood products at any time during the
             study.